<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>p3_CSS常用值</title>
    <style>
        h1{
            color: red;
            color:rgb(0,0,255);
            color:rgb(0,255,0);
            color:rgb(255,0,0);
            color:rgb(0,0,0);
            color:rgb(0,255,255);
            /*rgba带不透明度颜色1完全不透明0完全透明*/
            color:rgba(0,255,255,1);
        }
        .d1{
            width: 50px;
            height: 100px;
            background-image: url("img/mr.png");
            background-size: 50px,100px;
            background-color: cyan;
        }
        .d2{
            border: 5px solid red;
            width: 500px;
            height: 300px;
            background-image: url("img/mr.png");
            background-size: 500px 300px;
            background-color: cyan;
            /*不允许重复*/
            background-repeat: no-repeat;
            background-position: 0 0;/*背景图默认位置左上角*/
            background-position: -50px 0;
            background-position: center center;
            background-position: center;
            background-position: 100% 100%;
        }
        .d3{
            width: 500px;
            height: 300px;
            /*deg角度*/
            background-image: linear-gradient(45deg,red,orange,yellow,green,blue,purple);
        }
    </style>
</head>
<body>
<h1>测试颜色</h1>
<div class="d1"></div>
<div class="d2"></div>
<div class="d3"></div>
</body>
</html>